305,610 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ecophysiological response of maize (Zea mays L.) to water stress: remote sensing and upscaling techniques for a more efficient management of water resources in agriculture
No full textDispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Multiple production of W bosons in p p and p A collisions
No full textThe production of equal sign W boson pairs, through single and dou- ble parton collisions, are comparable in magnitude at the LHC. As a consequence of the strong anti-shadowing of MPI in interactions with nuclei, the double scattering contribution is further enhanced in the case of hadron-nucleus collision
Electrogenic bromosulfalein transport in isolated membrane vesicles: implementation in both animal and plant preparations for the study of flavonoid transporters
No full textBromosulfalein is an organic anion dye used in the study of a variety of membrane carriers expressed inanimal tissues and involved in transport of drugs and metabolites. The spectrophotometric assay of electrogenicbromosulfalein transport in membrane vesicles, isolated from various mammalian organs or tissues, enablesto specifically measure the transport activity of bilitranslocase (TCDB 2.A.65.1.1). The latter is a bilirubin- andflavonoid-specific transporter expressed in rat liver, the organ where its function has been better characterized. Thespectrophotometric assay of electrogenic bromosulfalein transport requires minimal volumes of membrane vesicles,is completed within 1 min, and, therefore, is a useful tool to screen the transporter spectrum of potential substrates,by testing them as reversible inhibitors of bromosulfalein transport kinetics. Furthermore, the assay enables tostudy the progress of time-dependent inactivation of bromosulfalein transport, caused by different protein-specificreagents, including specific anti-sequence antibodies. Inactivation can be retarded by the presence of substratesin a concentration-dependent manner, enabling to derive the dissociation constants of the transporter–substratecomplex and thus to gain further insight into the transporter structure–function relationship. This assay, implementedin membrane vesicles isolated from plant organs, has paved the way to the discovery of homologues of bilitranslocasein plants
Effect of 6-ketocholestanol on FCCP- and DNP-induced uncoupling in plant mitochondria
No full textEffect of 6-ketocholestanol on FCCP-induced and DNP-induced uncoupling in beef liver and pea stem mitochondria was studied, under experimental conditions at which this steroid abolished the effect of low concentrations of FCCP and other most potent uncouplers in rat mitochondria [Starkov et al. (1994) FEBS Lett., 355, 305–308]. It is shown that, in both types of mitochondria, 6-ketocholestanol prevents or reverses the uncoupling induced by low concentrations of FCCP, but not that caused by high concentrations of FCCP or by any concentration of DNP. Progesterone and male sex hormones, showing recoupling capability in animal mitochondria, appear to be ineffective in the plant system. Cholesterol does not recouple in both animal and plant mitochondria. Plant steroids, such as β-sitosterol and stigmasterol, are also without effect
Effect of cyclosporin A on energy coupling in pea stem mitochondria
No full textEffect of cyclosporin A on energy coupling in pea stem mitochondria is studied. It is found that incubation of mitochondria with 100 nM FCCP and/or CAtr, oligomycin, CaCl2, palmitate and ADP results, after some lag phase, in a collapse of Δψ generated by Succinate oxidation in the presence of rotenone. Cyclosporin A (0.2-0.8 nmol/mg mitochondrial protein) markedly increases the lag phase. The cyclosporin A effect requires dithioerythritol to be added to the isolation medium. Metabisulphite fails to substitute for dithioerythritol. The relationships between these effects and cyclosporin A-sensitive mitochondrial permeability transition in animal mitochondria are discussed
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
No full textThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
The role of mild uncoupling and non-coupled respiration in the regulation of hydrogen peroxide generation by plant mitochondria
No full textThe roles of mild uncoupling caused by free fatty
acids (mediated by plant uncoupling mitochondrial protein
(PUMP) and ATP/ADP carrier (AAC)) and non-coupled
respiration (alternative oxidase (AO)) on H2O2 formation by
plant mitochondria were examined. Both laurate and oleate
prevent H2O2formation dependent on the oxidation of succinate.
Conversely, these free fatty acids (FFA) only slightly affect that dependent on malate plus glutamate oxidation. Carboxyatractylate (CAtr), an inhibitor of AAC, completely inhibits oleate- or laurate-stimulated oxygen consumption linked to succinate oxidation, while GDP, an inhibitor of PUMP, caused only a 30% inhibition. In agreement, CAtr completely restores the oleate-inhibited H2O2formation, while GDP induces only a 30% restoration. Both oleate and laurate cause a mild uncoupling of the electrical potential (generated by succinate), which is then followed by a complete collapse with a sigmoidal kinetic. FFA also inhibit the succinate-dependent reverse electron transfer.
Diamide, an inhibitor of AO, favors the malate plus glutamate dependent H2O2formation, while pyruvate (a stimulator of AO) inhibits it. These results show that the succinate-dependent H2O2 formation occurs at the level of Complex I by a reverse electron transport. This generation appears to be prevented by mild uncoupling mediated by FFA. The anionic form of FFA appears to be shuttled by AAC rather than PUMP. The malate plus glutamate-dependent H2O2 formation is, conversely, mainly
prevented by non-coupled respiration (AO)
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